Clean-room by design
Readable, original C++20 code and carefully documented evidence keep the new implementation separate from proprietary source code.
Work in Progress
An empire. A new beginning.
The first recomp project for Emperor: Rise of the Middle Kingdom.
An independent clean-room reimplementation in C++20 and SDL3, beginning with a native Apple Silicon sandbox and a long road toward a modern way to revisit a city-building classic.
The project
Rebuilding a classic, cleanly.
OpenEmperor is written independently from documented behavior and original research. It does not distribute the original game, its data, or proprietary source code.
Your copy, your data
OpenEmperor reads files from your own legally obtained, installed or extracted copy of the original game. No original assets are bundled.
A modern foundation
SDL3, CMake, deterministic simulation, and bounded read-only asset tooling create a portable base that can grow beyond the initial Mac target.
0.1.0-alpha.1
A first playable sandbox — not the full empire.
The first public build is an experimental alpha for external testing. It proves the application shell, original-data setup, map loading, production loop, routing, and OpenEmperor saves. It is not yet a complete recreation of Emperor.
Read the known issuesWhat this alpha includes
- A main menu for selecting your own original game data and a supported standalone map
- The OpenEmperor Industry-v5 sandbox with roads, two clay sources, two potteries, one warehouse, four households, and five couriers
- Road placement and removal, production, supply, deterministic routing, and live rerouting
- OpenEmperor save and load support for the sandbox
- Optional local visual profiles for previewing walker, building, and road graphics supplied from your own game files
What it is not — yet
- A complete original-game experience or campaign recreation
- Compatible with original Emperor savegames
- A replacement for the original game data
- A notarized, production-ready macOS release
“Not a port. Not an asset pack. A new implementation, built from evidence and tested one system at a time.”
Before you begin
Bring the original. OpenEmperor brings the new foundation.
The alpha is intentionally narrow. Make sure you have the required hardware and data before downloading.
Apple Silicon Mac
The first packaged alpha targets macOS on arm64. Linux, Windows, and Intel Mac builds are not part of this release.
Original game data
You need a legally obtained, installed or extracted copy of Emperor: Rise of the Middle Kingdom. The GOG installer file itself is not a data folder.
Get Emperor on GOGAlpha expectations
The app is ad-hoc signed and not notarized. macOS may show a security warning, and incomplete visuals or diagnostic fallbacks are expected.
First run
From archive to sandbox.
- 1Download
Get OpenEmperor 0.1.0-alpha.1 from the GitHub release page.
- 2Extract
Unzip the archive and open OpenEmperor.app on an Apple Silicon Mac.
- 3Select your data
Choose the folder containing your installed or extracted Emperor game files, then start a supported sandbox map.
The road ahead
Built one verified layer at a time.
Development continues through small, testable systems: safer file interpretation, stronger visual compatibility, deeper authored sandbox rules, and a portable architecture. Each step keeps research evidence, original-game behavior, and OpenEmperor-authored mechanics clearly separated.
Questions
Before entering the sandbox.
Is OpenEmperor the original game?
No. It is an independent clean-room reimplementation and currently an experimental sandbox, not a complete recreation of Emperor: Rise of the Middle Kingdom.
Does the download include Emperor assets?
No. You must supply files from your own legally obtained, installed or extracted copy of the original game.
Which systems does the first alpha support?
The packaged 0.1.0-alpha.1 release is built and tested for macOS on Apple Silicon.
Enter carefully
Help test the first foundation.
Try the experimental sandbox, read the known limitations, and report reproducible problems without uploading original game files.